In a refrigeration system a compressor is used to produce a high refrigerant pressure gas which is subsequently liquefied by a condenser. The compressor has moving parts which must be lubricated in order to ensure reliable operation and longevity. Oil which is delivered to the moving parts of the compressor collects in a bottom of a compressor crank case and is recirculated: by a pump, or by refrigerant gas circulation through compressor, to the moving parts.
A crank case heater is sometimes used to heat the oil during a cycle OFF mode of the refrigeration system. This keeps the oil warm and prevents refrigerant migrating back to the crank case. In addition in cooler weather conditions, heating the oil maintains a minimum viscosity which assists in ensuring the quick application of lubricant to moving parts upon the refrigeration system switching to a cycle ON mode.
Oil management systems for compressors are well established in the market. Mechanical systems like the system per example from AC&R Components or the electronic system from per example Henry Technologies or Traxon Industries Pty Ltd.